EP1321329A2 - Vehicle with double clutch multiple gear transmission - Google Patents

Abstract

The transmission has an actuator (56) which is able to produce variable-setting gear shift forces, as calculated by the control unit (36) on the basis of input data and-or service state of the transmission or clutches (24), and-or the drive unit, and/or the vehicle as a whole, so that the correct gear is selected at all times.

Description

The invention relates to a motor vehicle with a multi-clutch multi-speed transmission, especially dual clutch multi-speed transmission. Something More specifically, the invention relates to a motor vehicle with a drive train, the one drive unit, a transmission with a first and a second transmission input shaft and a multiple clutch device, in particular double clutch device, with one of the first transmission input shaft assigned first clutch arrangement and one of the second transmission input shaft associated second clutch assembly for torque transmission between the drive unit and the gearbox has, wherein a control device is provided, by means of which an actuator assigned to or associated with the transmission to a respective one of the first and the second transmission input shaft Transmission gears can be engaged and disengaged and by means of one of the coupling devices assigned or associated actuators the clutch arrangements can be operated. The invention further relates to a method for Shifting a multiple clutch transmission, especially a double clutch transmission, and a corresponding control device.

• Aus der DE 195 26 273 C2 ist es bekannt, die Schaltkraft während eines Einrückens einer Schaltgangstufe zu variieren und während der eigentlichen Synchronisierphase mit niedriger Schaltkraft zu agieren.
• Aus der DE 100 01 486 C1 ist es bekannt, Schalthäufigkeiten (Zahl der bisher erfolgten Schaltvorgänge) und die Fahrbahnneigung bei der Bestimmung der Schaltkraft in bestimmten Gangschaltstufen zu berücksichtigen.
• Aus der DE 199 61 117 A1 ist es bekannt, die Schaltkraft abhängig vom Betriebszustand des Kraftfahrzeugs zwischen einem niedrigen und einem hohen Schaltkraftverlauf umzuschalten.
• Die DE 199 41 011 A1 schlägt vor, die Größe einer Ausrückkraft zum Ausrücken eines Kupplungsglieds variabel einstellbar vorzusehen und die Größe der Ausrückkraft in Abhängigkeit von dem an der zu lösenden Gangstufe übertragenen Drehmoment oder/und der Änderungsgeschwindigkeit dieses Drehmoments zu bestimmen.

Variably adjustable shifting forces for engaging or disengaging transmission gears are already state of the art in connection with single clutch transmissions. The adjustable variability primarily serves to protect the synchronizing devices of the transmission so that they do not wear out prematurely. In automated single-clutch manual transmissions (ASG), transmission actuation with variably adjustable shifting forces has already found its way into series production. The following writings can be referred to as prior art:

• From DE 195 26 273 C2 it is known to vary the shifting force during engagement of a shift gear stage and to act with a low shifting force during the actual synchronization phase.
• From DE 100 01 486 C1 it is known to take into account shifting frequencies (number of shifts previously carried out) and the inclination of the road when determining the shifting force in certain gear shift stages.
• From DE 199 61 117 A1 it is known to switch the shifting force between a low and a high shifting force curve depending on the operating state of the motor vehicle.
• DE 199 41 011 A1 proposes to provide the size of a disengagement force for disengaging a clutch member in a variably adjustable manner and to determine the size of the disengagement force as a function of the torque transmitted at the gear stage to be released or / and the rate of change of this torque.

More recently, they have so-called multiple and double clutch devices with a first transmission input shaft first clutch arrangement and a second transmission input shaft associated second clutch arrangement found greater interest, because this is a driving comfort similar to that of a fully automatic transmission promise with torque converter, but are more energy efficient. Through a so-called "overlap circuit" is a sequential Switching between transmission gears possible without interrupting the tractive force. In addition, it is assigned to a currently not load-transferring Transmission input shaft in the non-engaged state of the assigned Clutch assembly inserted a gear and then on top of each other matched the currently engaged, load-transmitted gear (the output gear) associated clutch assembly and assigned to the additionally engaged gear (the target gear) Coupling arrangement operated in opposite directions, namely synchronously the Output gear assigned clutch arrangement disengaged and the Target gear assigned clutch arrangement engaged.

The invention proposes, also in so-called double clutch transmissions (generalized multiple clutch transmissions) variably adjustable Provide switching forces. For the motor vehicle mentioned at the beginning Specifically suggested that the associated or associated with the transmission Actuator system is designed for variably adjustable switching forces on switching elements of the transmission and that the control unit is designed for it is occurring switching requirements based on input data or / and operating states of the transmission or / and operating states the coupling device and / or operating states of the drive unit or / and driving states of the motor vehicle different switching forces or assign shift force curves and by means of the gearbox associated or associated actuators relevant gears with the each assigned shift force or the respectively assigned shift force curve to insert or / and relevant gears with the respectively assigned Shifting force or the respectively associated shifting force curve interpreted. It is mainly thought that the control unit for this is designed, first switching requirements low switching forces or Assign shift force curves with lower shift forces and second Switching requirements with higher switching forces or switching force curves assign higher switching forces.

The variably adjustable switching forces can relieve pressure on the one hand the synchronizers of the transmission can be achieved and on the other hand but for a subjectively sufficient reaction speed from the driver's point of view be concerned about the gearbox operation. For this it is specifically suggested that the first switching requirements be such Switching requirements include that are not in immediate response to a Influence of the driver on an operating arrangement of the vehicle occur. The switching requirements to be identified as the first switching requirements can be in a fully automatic mode, for example occurring switching requests act, for example, in a D operating state the fully automatic functionality without driver intervention occur.

It is also specifically suggested in this context that the second switching requirements include those switching requirements that in immediate reaction to an influence of the driver on an operating arrangement of the vehicle. The second switching requirements Switching requirements to be identified can also be in switching requirements occurring in a fully automatic mode that For example, when the accelerator pedal is pressed hard (so-called Kick-down). In such cases, the driver expects a spontaneous one Reaction of the "automatic transmission", which is why after this training proposal the switching requirements in question higher switching forces or switching force profiles with higher switching forces.

The second switching requirements can in particular also be such switching requirements comprise by the driver by means of a / the operating arrangement be signaled as an acute shift request. It will be in this Connection, for example, in a fully automatic mode or in switching requests occurring in a manual mode, for example to driver commands that sequentially advance the Specify gearbox. For this purpose it is called "Tiptronic" in the Known in the art known gearshift modes, in which the Driver, for example, a rocker switch or in an extra lane arranged gear selector operated (see, for example, DE 199 12 963 A1).

The control device can advantageously be designed for preparation an overlap circuit in which in association with one currently load-transmitting the transmission input shafts an output gear and in association with a transmission input shaft that is not currently transmitting the load a target gear are engaged at the same time and then that of clutch arrangement previously assigned to the load-transmitting transmission input shaft in terms of disengagement and that of those who have not yet transferred the load Gearbox input shaft assigned clutch arrangement in the Is actuated on the basis of input data to determine a probable target gear and assign it to the currently non-load-transmitting transmission input shaft as potential Target gear in addition to one assigned to the current load transfer Gearbox input shaft inserted, the output gear of the gear to be prepared for the overlap circuit (hereinafter referred to as the exit corridor).

This proposal for further training can be specifically referred to in DE 199 37 716 C1 are referred. This patent suggests a gearbox assigned electronic control device as "Gait prognostic and Gear selection device "by means of which current Operating data can be predicted even before a gear change is requested is whether a gear change is likely to be required in the future and what the future course is likely to be, the Control device when such a future gear change is likely appears, this by means of the gear actuator for preparation of the overlap circuit. Depending on the Operating data for the gear forecasting and gear selection function of the Control device exists according to the explanations in the patent for the controller has the ability to make the following decisions: None Possible statement or high probability of an upshift (from a lower exit gear to a higher target gear) or high Probability for a downshift (from a higher output gear in a lower target gear). It should be noted that the proposal the patent over other prior art at least in an overall view (cf. DE 40 31 851 A1, EP 0 827 861 A2, DE-PS 923 402, DE 197 51 456 A1 and trade journal "Automotive Engineering, Feb. 1983, pp. 80-82) contains little new.

The patent specification does not contain any details on which Way the operational data is evaluated and how from the different, in operating data referred to in the patent, the probabilities mentioned be determined.

Even if the specialist has completed the teaching of DE 199 37 716 C1 is left to the proposal of the patent underlying intention makes perfect sense. With a multiple clutch transmission, especially dual clutch transmission, it is namely desirable for various reasons, the actions of one "Anticipate" the driver and, based on this knowledge, the next one The driver has already selected the desired gear. It can then immediately to the driver issuing a switching command (for example manually by operating a gear selector lever or shift paddles or by depressing the accelerator pedal to initiate such a process called kick-down circuit) the overlap circuit without time delay to be triggered. Especially with kick-down circuits the driver expects a spontaneous reaction from the vehicle, which only realizes can be used if the next lower gear is already engaged.

Spontaneous acceleration requests from the driver, which requires a downshift make necessary z. B. Situations where the driver for a long time at a relatively constant speed behind you slow moving vehicle and a favorable traffic situation wants to use to overtake.

To that extent, the mentioned patent specification DE 199 37 716 C1 points to the right direction, but there are still no proposals, such as the "right" Target gear can actually be predicted based on the input data should.

As far as the preparation of an overlap circuit for Going to a lower gear, you might think prefers to use the next lower gear as a potential target gear, to react spontaneously to downshift commands.

Such "provision" of a lower gear is not always the case be the right choice, because then an "unexpected" coming upshift command First the gear provided and the desired one higher gear needs to be engaged, which becomes clear for the driver noticeable inertia of the system.

In addition, when a lower gear is provided, the gearbox turns Half of the coupling arrangement in question and all assigned Wheels and shafts of the gearbox up to the additionally inserted lower one Gear step relative to the gear step of the closed (load-transmitting) Clutch assembly faster and must therefore with each acceleration co-accelerated or braked, what from Energy efficiency is disadvantageous. Furthermore, the speed of the inserted gear is monitored to prevent damage and if a limit speed is exceeded, the gear selected is re-engaged become. If the time limit is exceeded again, the potential (Lower) target gear can be reinserted to a possible Downshift command to react spontaneously.

In contrast, it is proposed as particularly preferred that the Control device is designed to have an increased probability of a downshift to a lower one compared to the exit gear Target gait based on the setting of a flashing signal and / or on the basis to recognize a steering operation that exceeds a minimum actuation and a corresponding gear as a potential target gear by means of the Actuate actuators.

One aspect of this proposal for further training lies in the idea that the driver, provided he complies with the traffic rules behaves correctly, an intended overtaking first by setting a blinker signal to the other road users, in particular the road user driving ahead to be overtaken and also a possibly subsequent road user, announces and only after the flashing signal has been set by actively switching back or by Depressing the accelerator pedal actually initiates the overtaking process.

This information given to the other road users as such registered by a sensor or a controller and sent to the control device could be passed on, the control device can evaluate and from that an increased likelihood of coming soon derive a downshift command and a one engage the corresponding lower gear as a potential target gear, so to be able to react spontaneously to the expected downshift command.

In order to stick to the example of an overtaking maneuver, one such in usually through a fast, comparatively strong steering movement initiated. In another aspect, it is therefore proposed that Evaluate steering movements of the driver accordingly, from which if necessary an increased likelihood of a short downshift command derive to a lower gear. Above all, it will thought that the control device is designed to increase the probability for downshifting based on a minimum steering angle exceeding steering angle and / or based on a Minimum steering angular speed exceeding steering angular speed to recognize.

In a further development it is further proposed that the control device for this is designed, by means of the actuator system assigned to the coupling device that assigned to the transmission input shaft, which has not yet been load-transmitting Coupling arrangement for preparing the overlap shift partially, preferably until a friction limit is reached. The clutch arrangement in question can be indented so far, for example that they are just a minor or just no Transmits moment. Through this "preparatory" engagement of the clutch assembly can respond immediately to a downshift command and the overlap circuit be made without first completing the finish to have to bring assigned clutch assembly into a "start position".

It can advantageously be provided that the control device for this is designed on the basis of current and / or previous Driving conditions or / and on the basis of navigation data and / or on Basis of actuation conditions dependent on the actuation by a driver or / and based on states of the transmission or / and the drive unit or / and the coupling device or / and permissibility based on other conditions of the motor vehicle or it makes sense to insert one in relation to the exit gear check lower target gear and a corresponding gear than potential target gait in response to the flashing signal or in Reaction to the steering actuation exceeding the minimum actuation only in the event of an affirmative appeal. This can take various circumstances into account become. For example, the control device should insert lower gear only when downshifting Speed limits, such as the drive unit (of the motor), not exceeded become.

Furthermore, the control device according to the suggestions in the mentioned patent DE 199 37 716 C1 can be designed. The revelation this specification is fully incorporated by reference into the disclosure included in the present application.

In connection with the preparatory insertion of a potential According to the invention, it is particularly preferred that the control device is designed by means of the gearbox or associated actuator technology the potential target in the sense of a first Shift request with a lower shifting force or a shifting force curve to be engaged with lower shifting forces.

In practice it will at least occasionally happen that the then the target gear actually needed is not the potential one already inserted Target gear corresponds. In this case the precautionary must already be inserted Gear again and then put the "right" target gear, which results in a corresponding extension of the switching times. Around keeping these switching times within the range can advantageously be provided that the control device is designed, when a switching request occurs, according to which one different from the potential target entered Target gear is to be engaged by means of the or assigned to the transmission associated actuator technology the potential target in the sense of a second switching request with a higher switching force or one To design shifting force curve with higher switching forces and by means of Actuators assigned to or associated with the transmission are those that have occurred Shift request corresponding target gear in the sense of a second Shift request with a higher shifting force or a shifting force curve with higher shifting forces. But this can also be done another distinction between "in a hurry", for example immediately by switching actions triggered by the driver and less "Hurry", for example not due to the driver acting Shift requirements are made to meet the higher shifting forces or the shifting force curves with higher shifting forces only then to be used if there are "urgent" switching requirements.

After performing an overlap shift is used to lay out the exit aisle, if this is to be designed at all, usually enough time is available. Accordingly proposed that the control device be designed after implementation a / the overlap circuit, in which in association with a currently an output gear transmitting the transmission input shafts and in association with a the currently not load-transferring Transmission input shafts are engaged and then a target gear at the same time the clutch arrangement assigned to the previously load-transmitting transmission input shaft in terms of disengagement and that of those who have not yet transferred the load Gearbox input shaft associated clutch assembly in Is actuated in the sense of an engagement, by means of the associated with the transmission or associated actuator system the output gear in the sense of a first shift request with a lower shifting force or a Gearshift force curve to be designed with lower gearshift forces.

The control device can advantageously be designed for when it is stationary Motor vehicle and / or in driving conditions of the motor vehicle with a vehicle speed not exceeding a threshold all Identify occurring switching requests as the first switching requests or / and the switching requirements that occur to make sense check and only one for switching requirements identified as sensible engage the relevant gear or a relevant gear interpreted.

It is thought of, for example, nonsensical switching requirements completely ignored when the vehicle is stationary. It usually makes sense be to only allow gearshifts in start-up gear and all others Ignore switching requests. As far as switching requirements make sense are, it will usually be sufficient, these with low switching forces perform.

Nonsensical switching requests can occur, for example, if, for example, a bored driver waits at a Traffic lights wantonly playing around with the paddle shifters or the like, for example to the beat of the music from a switched on car radio. Wilde, Uncoordinated gearshifts in the transmission can be made according to the training proposal be prevented. Such uncoordinated circuits will be not necessarily wear out the synchronization devices heavily as the gear shafts do not turn when the vehicle is stationary. by virtue of the shifting forces can other components, such as shift forks, Sleeves, etc., unnecessarily stressed.

It has at least been implied that the control device can be designed depending on input data gear change by means of the actuator system assigned or associated with the transmission to be carried out fully automatically or automatically. In this regard, it can be provided that the control device is in a fully automatic mode provides in which the gear change fully automatically depending of driving states and / or operating states of the vehicle become. Furthermore, the control device can have a manual mode provide in which the gear change depending on a Operating arrangement given by the driver switching commands performed become.

The invention further relates to a control device for an inventive Motor vehicle. It is proposed that one assigned to the transmission Control device is designed to meet switching requirements on the basis of input data and / or operating states of the Gearbox and / or operating states of the coupling device or / and Operating states of the drive unit and / or driving states of the motor vehicle assign different switching forces or switching force profiles and by means of an associated or associated with the transmission Actuator-related gears with the respectively assigned shifting force or to insert the respectively assigned shifting force curve or / and relevant gears with the respectively assigned shifting force or the to design each assigned shift force curve. The invention Control device can correspond to the control device of the invention Motor vehicle as described above.

The invention further relates to a method for shifting a multiple clutch transmission, especially double clutch transmission. It will suggested that occurring switching requests based on Input data and / or operating states of the transmission or / and operating states the coupling device and / or operating states of the Drive unit and / or driving conditions of the motor vehicle different Switching forces or switching force profiles are assigned and mediated an actuator assigned to or associated with the transmission relevant gears with the respectively assigned shifting force or the each assigned shift force curve inserted and / or relevant Gears with the respectively assigned shift force or the respectively assigned Switching force curve can be designed. Advantageous further training of the method according to the invention result from the foregoing Versions.

Fig. 1

zeigt schematisch einen Kraftfahrzeug-Antriebsstrang mit einer Lamellen-Doppelkupplung und einem Lastschaltgetriebe, der eine erfindungsgemäße Steuereinheit aufweist.

Fig. 2

zeigt schematisch eine Abwandlung des Antriebsstrangs gemäß Fig. 1, nach der statt einer nasslaufenden Lamellen-Doppelkupplung eine trockenlaufende Doppelkupplung der Reibscheibenbauart vorgesehen ist.

Fig. 3

zeigt ein exemplarisches Flussdiagramm betreffend die Zuordnung von kleineren und größeren Schaltkräften zu Schaltanforderungen.

Fig. 4

zeigt eine Variante des Flussdiagramms der Fig. 3.

The invention is explained in more detail below on the basis of exemplary embodiments illustrated in the figures.

Fig. 1

schematically shows a motor vehicle drive train with a multi-plate clutch and a powershift transmission, which has a control unit according to the invention.

Fig. 2

1 schematically shows a modification of the drive train according to FIG. 1, according to which a dry-running double clutch of the friction disk type is provided instead of a wet-running multi-plate clutch.

Fig. 3

shows an exemplary flow chart regarding the assignment of smaller and larger switching forces to switching requirements.

Fig. 4

shows a variant of the flow diagram of FIG. 3.

1 shows an example of a drive train 10 of a motor vehicle. The drive train has a drive unit 12 in the form of an internal combustion engine, specifically of an internal combustion engine, as if symbolic drawn crankshaft 14 is indicated. A so-called powershift transmission 18 with two radially nested transmission input shafts 20 and 22 is connected to the engine 12 via a double clutch 24. The double clutch 24 comprises two clutch arrangements 26 and 28, one of which is the transmission input shaft 20 and the other of the transmission input shaft 22 is assigned. Acting in the embodiment it is wet-running multi-plate clutch arrangements that mediate of a respective hydraulic slave cylinder integrated in the double clutch (not shown) can be actuated hydraulically. A corresponding hydraulic pump 30 is shown schematically. One of the Double clutch assigned cooling oil circuit with a cooling oil pump etc. is not shown. Suitable double clutch designs are, for example known from DE 100 04 179 A1.

The actuation of the two clutch arrangements takes place through mediation of control valves 32 and 34 that are electrically controlled by a control unit 36 are controllable. The control unit receives input signals from one Accelerator pedal 38, a gear selector and / or influencing unit 39, one the transmission input shaft 20 associated speed sensor 40, one of the Gearbox input shaft 22 assigned speed sensor 42 and one of the Engine output shaft (crankshaft 14) associated speed sensor 44. Die Control unit can also other signals and measurements from others Sensors and signal transmitters, such as a vehicle speed sensor, a steering angle sensor, a brake actuation state sensor (such as the brake pedal 46 shown in FIG. 1), etc.

By comparing the speed of the speed sensor 44 on the one hand and the Speed of the speed sensor 40 or 42 on the other hand, the control unit a slip state of the clutch arrangement 26 or the clutch arrangement 28 determine. The control unit 36 controls a power actuator of the engine 22 in order to increase the power or adjust the torque given by the engine.

In Fig. 1, a crankshaft starter generator 50 is shown, the one on Motor 12 arranged stator assembly and one on the input side of the Double clutch 24 arranged rotor assembly. The crankshaft starter generator 50 is activated by the control unit 36, in particular to start the engine 12.

To the powershift transmission, which can also be called a double clutch transmission 18 it should also be noted that it is preferably a fully synchronized one Gearbox acts with a corresponding synchronizing device 52. The synchronization device 52 does not need to be a central one Act synchronizer for the whole transmission. The synchronizer can also from conventional synchronizers, such as in the form of synchronizer rings. An output shaft of the transmission is designated 54. The transmission is preferably fully automated by means of a correspondingly controllable by the control unit 36 Actuator 56 actuated. By means of the gear selection or / and influencing unit 39, the driver can instruct the control unit 36 to to shift down to a lower gear or to a higher gear upshift. The control unit switches in a fully automatic mode automatically depending on the driving and operating conditions of the vehicle.

The switching between an output gear and a target gear takes place in usually by means of a so-called "overlap circuit" which assumes that in addition to the currently load-bearing output gear in association with the other transmission input shaft that is not currently transmitting the load the target gear is already engaged, but the one is not Coupling arrangement assigned to the load-transmitted transmission input shaft is disengaged. Then during the overlap circuit currently load-transmitting clutch arrangement assigned to the output gear in terms of disengagement and the one assigned to the target gear Coupling arrangement coordinated in terms of an engagement actuated to drive the drive unit from the output gear assigned transmission input shaft and thus from the output gear to the gearbox input shaft assigned to the target gear and thus to To shift target gear.

2 shows a further example of a drive train 10 of a motor vehicle. Only the changes to the powertrain 1 explained. Instead of a double clutch 24 with two wet-running Multi-plate clutch arrangements 26 and 28 is in the example of Fig. 2 shows a double clutch 24 with two dry-running clutch arrangements 26 and 28 of the friction disc type are provided. The two friction disc clutch assemblies can for example by means of Double clutch integrated hydraulic slave cylinders on hydraulic Be able to be actuated, which is assumed in Fig. 2. Appropriate Implementation options are, for example, from DE 35 26 630 A1 removable. But it can also be constructed entirely differently dry-running double clutches are used, for example refer to EP 0 931 951 A1.

Is a switching command given manually by means of the unit 39 or on the one made by the control unit 36 in the fully automatic mode Decision to switch by means of an overlap circuit only If the target gear is still engaged, driving comfort may occur noticeable delays. The control unit 36 is therefore preferably carried out with a gait forecast functionality, which, depending on input data, a probable one Predicts target gear and this in preparation of an expected overlap shift already inserted, although by means of the unit 39 still no switching command is given or a decision in fully automatic mode not yet liked to switch. To this extent, the control unit 36 can according to the gait prognostication proposed in DE 199 37 716 C1 and gear selector and various Process operating data as input data. It is based on revelation of DE 199 37 716 C1, which is incorporated by reference into the Disclosure of the present patent application is included.

With a view to preparing a downshift to a lower one Gear, control unit 36 is preferably specially designed to an increased likelihood of downshifting versus one the finish gear lower finish gear based on seating a blink signal and identify a corresponding gear as potential Engage target gear by means of the actuating device 56. Further is the control device according to a preferred embodiment therefor designed by appropriate actuation of the valve assembly 32, 34 for Preparation of the overlap circuit is a precaution engaged clutch arrangement, previously not load-transmitting clutch arrangement partially indent, preferably until reaching one Friction limit so that on a switching command or on the decision trigger a shift immediately, d. H. without time delay, the overlap circuit can be performed.

Regarding the precautionary insertion of one at the moment load transfer gear (the output gear) lower potential Target gear based on the setting of a flashing signal is in the exemplary embodiments 1 and 2 provided that a corresponding Turn signal control signal from a turn signal switch 60 alone or additionally is supplied to the control unit 36. Operates the driver to announce the turn signal switch 60 during an overtaking maneuver, the control unit can 36 on the basis of the turn signal control signal supplied to it Probability of an upcoming shift to a lower one Recognize the target gear and in response to the lower one concerned Engage gear (the potential target gear).

It makes sense to generally operate the turn signal switch by the driver of an increased likelihood of insertion a lower target gear compared to the current gear. Even with turning processes, which are carried out in accordance with regulations by a corresponding Blink should be announced, usually either maintain the current gear or go to a lower gear connected.

Alternatively or additionally, the control unit 36 can have an increased probability for an upcoming shift to a lower target gear recognize based on steering movements and in response to it engage the lower gear concerned (the potential target gear). 1 (the same can also be said for the embodiment of FIG 2) the control unit 36 receives signals from one Vehicle steering device 62. It could be provided, for example, that a current steering angle or changes in the current Steering angle (possibly a steering angle speed) by a corresponding sensor detected and in the form of corresponding signals from the Control unit 36 are supplied. Because in particular overtaking maneuvers in usually initiated by a pronounced steering maneuver the probability of a impending shift to the lower target gear in order to achieve a detect high vehicle acceleration.

The control unit can use various other input data in its forecast of a particular target. The control unit can the admissibility or meaningfulness of inserting one in itself Check the predicted target route and, if necessary, despite an existing one Prediction that a particular finish is likely to come soon should be activated by the precautionary engagement of this gear as anticipate potential finish. This check for admissibility or Meaningfulness can also be useful in relation to one Exit gear lower target gear take place, for example, to ensure that in the case of a downshift, speed limits (approximately the preferred drive unit designed as an internal combustion engine) is not exceeded become.

The control unit 36 is designed according to the invention, depending of input data and / or operating states of the transmission or / and Operating states of the coupling device and / or operating states the drive unit and / or driving conditions of the motor vehicle Shift requirements different shift forces or shift force curves assign and by means of the gear actuator (valves 32, 34 and hydraulic slave cylinders assigned to the clutch arrangements) relevant gears with the respectively assigned shifting force or the to insert in each case assigned shift force curve and / or concerned Gears with the respectively assigned shift force or the respectively assigned To design the shifting force curve. As a rule, it will be sufficient between first or "less urgent" switching requirements and second or to distinguish "more urgent" switching requirements and the first or "less urgent" switching requirements low switching forces or switching force profiles assign with low switching forces and the second or "more urgent" switching requirements higher switching forces or switching force profiles assign with higher switching forces.

For circuits in a fully automatic mode of the control unit 36, at which the driver expects gearshifts, but their exact When the time is not known, the control unit 36 reacts to operational characteristic data such as increasing or decreasing engine and / or transmission speed. The Control unit can then use the next gear to be shifted with relative engage low switching forces. That the relatively low shifting forces a correspondingly longer switching time is not considered by the driver Perceived time delay, since the driver does not know when the shift command was given. Due to the lower switching forces, the Protected synchronizing devices of the transmission.

A variation of the switching forces in different automatic modes is in the Principle possible within the scope of the invention, but at least with overlapping circuits not absolutely necessary as it is in the overlap circuit there is no interruption in tractive power.

However, it can also be unexpected in a fully automatic mode Shift requests occur where the driver has an immediate response expected of the vehicle, e.g. B. at a kick-down of the accelerator pedal. According to the above suggestions, the required gear is already as "potential target gear" has been inserted as a precaution, just need the overlap circuit can be performed.

In the event of an unforeseen or incorrectly anticipated shift request the driver, on the other hand, will not see any or a wrong one (regarding the Example "kick-down" a higher gear in the other, currently not load-transmitted gear shaft must be inserted. Then it must be in the former If the wrong gear is selected first, then, as in second case, the correct gear must be selected so that afterwards an overlap circuit can take place. The same applies to embodiments for which no precautionary engagement of transmission gears based on predictions or probabilities is. With regard to such switching requirements, higher is proposed Apply shifting forces to quickly select the right gear. If another wrong gear must be designed beforehand, should this be the case also be done as quickly as possible and there should be one accordingly high shifting force (release force) can be used.

However, as far as potential destinations are inserted as a precaution, this can happen with low shifting forces, because at the moment it is still at all no overlap circuit is pending.

When switching in a manual mode could refer to the two Embodiments of FIGS. 1 and 2 especially two types of circuits be distinguished in which the power flow from one to the other the other gear shaft is switched. On the one hand there are circuits occur in which the gear to be shifted only on the other gear shaft must be engaged because either no gear or the wrong gear is inserted. Furthermore, circuits will occur in which before the driver's shift request based on a corresponding prediction as a precaution the right gear (the potential target gear) on the another gear shaft is inserted.

As already mentioned in relation to the fully automatic mode, precautionary Circuits to a "potential target gear" by the "Gait prognostic device" made without an acute shift request are to be carried out with low shifting forces since in view due to the driver's lack of an acute shift request, nothing special There is a hurry. Driver switching requirements at which the selected Gear first engaged and possibly even an incorrect gear selected on the other hand, should have a comparatively high shifting force be made to the driver's acute shift request as quickly as possible to use. The shift requests are in a manual mode of the driver against potential switching requirements in an automatic mode much less predictable, so compared to Automatic mode should take place at which more switching requirements no gear or an incorrect gear engaged on the other transmission input shaft is.

Both in fully automatic mode and in manual mode can be provided be that different variables within a circuit Switching forces are used (cf. DE 195 26 273 C2).

According to the previous proposals, high switching forces are only at Need applied to put in or lay out the gears and otherwise comparatively low switching forces, so the total wear occurring on the synchronizing devices of the transmission minimized, and under the condition that the subjective reaction speed of the system from the driver's point of view, or not is significantly deteriorated. With an appropriate size From the driver's point of view, the system reacts adequately to "greater switching forces" fast. The "larger switching forces" themselves can also be a compromise between switching speed on the one hand and load on the Represent synchronizers on the other hand. Because of the lower Loads on the synchronizers by the "weaker Switching forces "can make the weight a bit stronger in this compromise be placed on the shorter switching times.

3 shows an example of a flowchart of a routine or one Part of a routine that runs in control unit 36 and shift requests assigns a respective switching force. The switching requirements can in addition to loading gears, also laying gears affect. According to a diamond 100, it is checked whether, in relation to a Shift request the correct gear is already engaged. Is that the case, there is no longer any need to shift gearboxes, but it is only the overlap circuit by appropriate Operate the clutch assemblies. The routine can already be ended.

According to diamond 102, it is checked whether it is a precautionary shift request is. If this is the case, the switching request is not urgent and can be carried out with a smaller switching force. If it is not a precautionary switching request, i.e. none Shift request by the gear prognostic functionality of the control unit 36 is initiated, it is checked according to diamond 104 whether it is to another switching request without an acute switching request by the Driver acts. If this is the case, there will also be a smaller shifting force set. On the other hand, it is a switching request to acute Shift request of the driver, so a larger shift force is set. So far applicable, the larger shifting force is on the one hand as a disengagement force to design an incorrectly inserted potential target as well as Insertion force for inserting the target gear corresponding to the shift request used.

According to the example in FIG. 4 it can additionally be provided that the Vehicle speed compared to a threshold speed will (diamond 106), and that only for the speed threshold exceeding Vehicle speeds the greater shifting force is set. In the process could also be a check for basic Permissibility or usefulness of switching requirements must be integrated. For example, it usually makes sense only when the motor vehicle is stationary Allow shifting in start-up gears and further shifting requirements to ignore. Unnecessary gear shifting due to wanton (Playful) actuation of shift paddles by the driver (for example to pass the time while waiting at traffic lights) reliably prevent this way.

Claims (19)

Motor vehicle with a drive train comprising a drive unit (12), a transmission (18) with a first and a second transmission input shaft and a multiple clutch device, in particular a double clutch device (24), with a first clutch arrangement (1) assigned to the first transmission input shaft (20). 26) and a second clutch arrangement (28) assigned to the second transmission input shaft (22) for torque transmission between the drive unit and the transmission, a control device (36) being provided by means of an actuator system (56) assigned or associated with the transmission transmission gears can be engaged and disengaged for a respective one of the first and second transmission input shafts, and the clutch arrangements can be actuated by means of an actuator system (32, 34) associated with or associated with the clutch device, characterized in that the actuator system (56) associated with or associated with the transmission outputs is set to exert variably adjustable shifting forces on shifting elements of the transmission, and that the control unit (36) is designed to respond to shifting requests that occur based on input data or / and operating states of the transmission or / and operating states of the clutch device or / and operating states of the drive unit or / and To assign driving states of the motor vehicle to different shifting forces or shifting force profiles and to engage gears with the respectively assigned shifting force or the respectively associated shifting force profile by means of the gears associated or associated with the actuator (56), and / or to select relevant gears with the respectively assigned shifting force or the respectively assigned shifting force profile interpreted. Motor vehicle according to claim 1, characterized in that the control unit (36) is designed to assign low shifting forces or shifting force profiles with lower shifting forces to first shift requests and to assign higher shifting forces or shifting force profiles with higher shifting forces to second shift requests. Motor vehicle according to claim 2, characterized in that the first switching requirements include those switching requirements that do not occur in direct reaction to an influence of the driver on an operating arrangement of the vehicle. Motor vehicle according to claim 2 or 3, characterized in that the second switching requirements include such switching requirements that occur in direct reaction to an influence of the driver on an operating arrangement of the vehicle. Motor vehicle according to one of claims 2 to 4, characterized in that the second shift requests include those shift requests which are signaled by the driver by means of the / an operating arrangement as an acute shift request. Motor vehicle according to one of Claims 1 to 5, characterized in that the control device (36) is designed to prepare an overlap circuit in which an output gear is assigned in association with an instantaneously load-transmitting transmission input shaft and in association with an currently non-load-transmitting transmission input shaft Target gear are engaged at the same time and then the clutch arrangement assigned to the previously load-transmitting transmission input shaft in the sense of disengagement and the clutch arrangement assigned to the previously non-load-transmitting transmission input shaft in the sense of engaging is actuated on the basis of input data to determine a likely target gear and assign it to the currently non-load-transmitting one Transmission input shaft as a potential target gear in addition to the output gear of the exercises to be prepared in association with the currently load-transmitting transmission input shaft reschneidungsschaltung representing gear (hereinafter referred to as output gear). Motor vehicle according to claim 6, characterized in that the control device (36) is designed to recognize an increased probability of a downshift to a lower gear compared to the exit gear on the basis of the setting of a flashing signal and / or on the basis of a steering actuation exceeding a minimum actuation and to engage a corresponding gear as a potential target gear using the actuator system (56). Motor vehicle according to claim 7, characterized in that the control device (36) is designed to recognize the increased probability of downshifting on the basis of a steering angle exceeding a minimum steering angle and / or on the basis of a steering angular speed exceeding a minimum steering angle speed. Motor vehicle according to Claim 7 or 8, characterized in that the control device (36) is designed, by means of the actuator system (32, 34) assigned to the clutch device, to partially prepare the clutch arrangement (26 or 28) associated with the transmission input shaft, which has not been load-transmitting up to now, in preparation for the overlap shift , preferably until a friction limit is reached. Motor vehicle according to one of claims 7 to 9, characterized in that the control device (36) is designed on the basis of current or / and previous driving conditions and / and on the basis of navigation data or / and on the basis of actuation by a driver dependent actuation states and / or on the basis of states of the transmission (18) or / and the drive unit (12) or / and the coupling device (24) or / and on the basis of other states of the motor vehicle the admissibility or expediency of engaging one in relation to the exit gear to check the lower target gear and only engage a corresponding gear as a potential target gear in response to the blinking signal being set if the answer is affirmative. Motor vehicle according to Claim 2 and one of Claims 6 to 10, characterized in that the control device (36) is designed to use the actuator (56) associated or associated with the transmission to identify the potential target gear in the sense of a first shift request with a lower shifting force or to engage a shifting force curve with lower shifting forces. Motor vehicle according to claim 2 and according to one of claims 6 to 11, characterized in that the control device (36) is designed, when a shift request occurs, according to which a target gear different from the inserted potential target gear is to be engaged, by means of the gearbox assigned or associated Actuator system (56) to design the engaged target gear in the sense of a second shift request with a higher shifting force or a shifting force curve with higher shifting forces, and by means of the actuator assigned or associated with the transmission, the target gear corresponding to the shift request that has occurred in the sense of a second shift request with a higher shifting force or to engage a shifting force curve with higher shifting forces. Motor vehicle according to one of Claims 1 to 12, in any case according to Claim 2, characterized in that the control device (36) is designed, after carrying out an overlap circuit / in which, in association with an instantaneously load-transmitting transmission input shaft, an output gear and in association with a target gear is currently engaged in a gear transmission shaft that is not currently load-transmitting, and then the clutch arrangement assigned to the previously load-transmitting transmission input shaft is disengaged and the clutch arrangement assigned to the previously unload-transmitting transmission input shaft is engaged by means of the actuators (56 ) to design the output gear in terms of a first shift request with a lower shifting force or a shifting force curve with lower shifting forces. Motor vehicle according to one of claims 1 to 13, in any case according to claim 2, characterized in that the control device (36) is designed to, when the motor vehicle is at a standstill and / or in the driving conditions of the motor vehicle with a vehicle speed not exceeding a threshold value, all switching requests that occur as first switching requests to identify and / or to check the shifting requirements that occur for meaningfulness and to engage or to select a gearbox in question only for shifting requirements identified as meaningful. Motor vehicle according to one of Claims 1 to 14, characterized in that the control device (36) is designed to carry out gear changes in a fully automated or automated manner as a function of input data by means of the actuator system (56) assigned or associated with the transmission. Motor vehicle according to one of claims 1 to 15, characterized in that the control device (36) provides a fully automatic mode in which the gear changes are carried out fully automatically as a function of driving conditions and / or operating states of the vehicle. Motor vehicle according to one of Claims 1 to 16, characterized in that the control device (36) provides a manual mode in which the gear changes are carried out as a function of shift commands given by the driver by means of an operating arrangement (39). Control device for a motor vehicle according to one of the preceding claims, characterized in that the control device (36) is designed for switching requirements that occur on the basis of input data and / or operating states of the transmission (18) or / and operating states of the clutch device (24) or / and operating states to assign different shifting forces or shifting force profiles to the drive unit (12) and / or driving states of the motor vehicle and to engage gears with the respectively assigned shifting force or the respectively associated shifting force profile by means of an actuator (56) associated or associated with the transmission (18) or / and the relevant gears to be interpreted with the respectively assigned shifting force or the respectively assigned shifting force curve. Method for shifting a multiple clutch transmission, in particular Double clutch transmission (18), when occurring Switching requirements based on input data or / and Operating states of the transmission (18) and / or operating states the coupling device (24) and / or operating states of the drive unit (12) and / or driving conditions of the motor vehicle different Switching forces or switching force profiles can be assigned and by means of an associated or associated with the transmission Actuators (56) related gears with the respectively assigned Shifting force or the respectively assigned shifting force curve inserted or / and relevant gears with the respectively assigned Switching force or the respectively associated switching force curve designed become.

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